Listeners:
Top listeners:
play_arrow
Paul Verschure on consciousness and distributed adaptive control CSN Podcasts
play_arrow
Edvard Moser on grid cells and entorhinal cortex CSN Podcasts
play_arrow
Giacomo Rizzolatti on mirror neurons and action understanding CSN Podcasts
play_arrow
Robert Axelrod on game theory and prisoner's dilemma CSN Podcasts
play_arrow
Adrian Owen on disorders of consciousness and vegetative state CSN Podcasts
play_arrow
Jonathan Whitlock on markerless motion capture and posterior parietal cortex CSN Podcasts
play_arrow
Luis Puelles on neuroanatomy and prosomeric model CSN Podcasts
play_arrow
Zoltan Molnar on subplate neurons and cortical development CSN Podcasts
Episode 14 14.03.2012
play_arrow
PLAY EPISODE
Can the brain’s visual wiring be explained by the same engineering principles that optimize telephone networks? Dmitri Chklovskii shows how predictive coding theory and lattice filters map onto real neural circuits, from fly photoreceptors to the mammalian LGN.
Subscribe for more from the Convergent Science Network podcast series.
Chklovskii bridges theoretical physics and neuroscience by applying adaptive signal processing frameworks to sensory systems. Building on Barlow’s redundancy reduction principle and the predictive coding work of Srinivasan, Laughlin, and Dubs, his group derives normative predictions for neural filter shapes with no free parameters: once you specify the natural stimulus statistics and signal-to-noise ratio, the optimal filter is uniquely determined. The biphasic temporal response and center-surround spatial receptive fields of retinal and LGN neurons emerge naturally as mechanisms for subtracting predictions from incoming signals, compressing redundant information.
The key evidence supporting this framework over simple biophysical explanations like after-hyperpolarization comes from stimulus-dependent filter changes. At high contrast, neurons show sharp biphasic responses with strong negative components; at low contrast, the filter shifts toward broader low-pass characteristics with weakened negative phases. This adaptive behavior matches predictive coding predictions but would require different physiological implementations at each contrast level, suggesting the filter shape is functionally optimized rather than a fixed biophysical artifact.
Chklovskii introduces the lattice filter as a specific circuit implementation where decorrelation occurs in hierarchical stages, each operating at a different timescale. This architecture predicts that LGN temporal receptive fields should be longer than retinal ones, which matches electrophysiological observations. It also predicts two distinct LGN cell types corresponding to forward and backward prediction error pathways, identifiable with the known lagged and non-lagged cell classes. At Janelia Farm, his group has reconstructed the connectome of the fly visual system through the first two neuropils, mapping approximately 10,000 synaptic connections among 50 neurons per processing column. The L1 and L2 large monopolar cells show response properties consistent with the dual pathways of a lattice filter, and inter-column connections provide the substrate for motion detection.
Tagged as:
lattice filter Neurons Predictions predictive coding Receptive Fields
About the author call_made
Both the triumphs of humanity and its most evil deeds have resulted from collaboration. In a time where humanity is required to aspire to the former and minimize the latter, the question arises of how collaboration arises and why it fails. Surprisingly, this phenomenon, so central to who we are, is not well understood. Hence, a collaborative effort is required to understand collaboration in its full biological, psychological, sociological, cultural, and economic complexity and to translate this understanding into operational impact. This series of podcasts is one step toward achieving these complementary goals. The Collaboration Podcast presents interviews with people who are central orchestrators of collaboration in various domains including business, government, science, art, health, sustainability, and the military. The discussions were conducted by Prof. Dr. Paul F.M.J. Verschure and members of the Program Advisory Committee of the Ernst Strungmann Forum on Collaboration (https://www.esforum.de/forums/ESF32_Collaboration.html) during 2021 and had the goal to sketch a map of opportunities, challenges, and obstacles in human collaboration. The forum took place in May 2022, and now we would like to share this series of interviews with a broader audience. The full report of the Forum will be published in 2023 by MIT Press. The podcast was produced by the Convergent Science Network (https://www.convergentsciencenetwork.org/). Context: The stability of social systems depends critically on realizing sustainable methods of “collaboration,” yet how and by which means collaboration is achieved is not clearly understood; neither are the conditions or processes that lead to its breakdown or failure. Collaboration can be understood as cooperation between agents toward mutually constructed goals. Part of the reason for our lack of understanding is that the phenomenon of collaboration is, by nature, a highly multidisciplinary problem, and effective research into its complexities has been difficult to achieve across the broad range of scientific and technical disciplines involved. The need for a fundamental understanding of collaboration, however, has become increasingly important. Not only does humankind demand answers as it attempts to address critical challenges at multiple scales (e.g., climate change, migration, enhanced automation, social and economic inequality), but ever-increasing technological and economic means of interconnecting people and societies are disrupting long-established, familiar patterns of how we interact. Radical technological changes that are ongoing have the potential to reshape collaboration in ways that are currently hard to predict or influence (e.g., by altering configurations in interaction, information creation, and modes of communication). On one hand, such changes could disrupt hitherto stable forms of collaboration by affecting critical communication channels and traditional roles, as can be observed in the rapidly changing patterns in governance, commerce, and social interaction. Conversely, technology could lead to the emergence of novel, successful forms of collaboration that deviate from traditional “hierarchical” architectures. Evidence of this can be seen in areas as diverse as highly automated manufacturing plants, the open science movement, collaborative software repositories, user-centered services, and the sharing of economy-based modes of organization. Without a fundamental understanding of the mechanisms, processes, and boundary conditions of collaboration, it is not possible to evaluate or predict which of these possible scenarios are sustainable or even plausible. The Forum “How Collaboration Arises and Why it Fails” (May 8–13, 2022, Location: Frankfurt am Main, Germany) Chairs: Andreas Roepstorff and Paul Verschure Program Advisory Committee: Jenna Bednar, Julia R. Lupp, Bhavani R. Rao , Andreas Roepstorff, Ferdinand von Siemens, and Paul Verschure
14.03.2012
Exploring the convergence of neuroscience, robotics, and AI through conversations with leading researchers since 2010.
A project of the Convergent Science Network Foundation.
© CSN Podcasts. Developed by IMCreative & WEBC
✖
✖
Are you sure you want to cancel your subscription? You will lose your Premium access and stored playlists.
✖
Be the first to leave a comment